Accumulator or cold water tank+pump

[sasha0120]

Hi

I own a flat on the third floor of a building. There is an issue with the building water supply due to which there is not enough water pressure and volume reaching our flat. At peak times of the day there is no water coming in the taps. Thames Water will not do anything about it because they guarantee supply of 1 bar at the building entrance and that is it. The building does not want to provide for a pump or tank to resolve the issue. Thus, I am left with trying to find a solution for my flat. I have a brand new megaflo boiler and have been recommended 2 options: 1) Install an accumulator that will provide a burst of 20-30min of water for a shower during peak times when the water supply is most impacted or 2) Install a cold water tank and a pump (or a pumped tank?) that will provide enough water supply. We have 2 bathrooms and showers in the flat. Option 1 is quoted at £1.5-£2.5k and Option 2 is significantly higher at £3-£4k. I do have the space in terms of cupboards for an accumulator or cold water tank. Attached pics of our current megaflo configuration. I would really appreciate some advice. Our new megaflo boiler cost us £3k last Decemeber so we dont want to spend on Option 2. However, I want to make sure that Option 1 works before committing to it. Any advice/help is much appreciated!

 

[snowhead]

Has the mains water pipe up to your flat been investigated?

Has the pressure at the incomer been checked at peak times?

Are there other flats on the same level, if so do they have issues?

Is the incoming pipe to the building adequate for the number of properties?

Does a single pipe rise through the building and split to each flat or does each flat have it's own pipe from the point of entry of the main service?

I assume whoever fitted the new Megaflo did not investigate, otherwise they wouldn't have recommended the Megaflo?

 

[sasha0120]

Hi Snowhead, thanks for your reply.

THe answer to all your questions is that the water coming into the building is not adequate but TW is not going to do anything about it. The pipe carrying the water up is just 16mm wide so not adequate by any stretch. However, the only other flat in the third floor has a tank inside the flat and is not affected. The other flats complain of reduced water pressure but obviously we are at the worst end of the spectrum being at the highest floor. THe Megaflo was installed 7 years ago and hasnt been a problem until a few months ago. To be clear, the water supply is the issue so even the kitchen tap connected to the mains is affected. I am looking to find a solution to my flat so that I can be independent of the building and TW issues. I was proposed two solutions indicated above so looking for the pros and cons of the above. Thanks!

 

[ShaunCorbs]

Need to have a break tank and pump and oversize the storage accumulator won’t help / solve your problems

 

[EvilDrPorkChop]

Not sure you've got the room but a Dab E.SyBox would be your solution.

DAB ESYBOX and ESYTANK Cold Water Booster & Storage Tank

The DAB E.sybox and E.sytank is our best selling all in one booster set and water storage tank for domestic and residential applications. The ESYTANK is a potable (drinking) water storage tank designed specifically for simple integration with the ESYBOX electronic water booster system. The...

www.completepumpsupplies.co.uk

 

[ShaunCorbs]

Not sure you've got the room but a Dab E.SyBox would be your solution.

DAB ESYBOX and ESYTANK Cold Water Booster & Storage Tank

The DAB E.sybox and E.sytank is our best selling all in one booster set and water storage tank for domestic and residential applications. The ESYTANK is a potable (drinking) water storage tank designed specifically for simple integration with the ESYBOX electronic water booster system. The...

www.completepumpsupplies.co.uk

Agree but I would add the extra tank as well to give you around 800l of stored water enough for around an hour at 15lpm output with nothing coming in

 

[sasha0120]

Need to have a break tank and pump and oversize the storage accumulator won’t help / solve your problems

Thanks for your input. Do you know if the pump will work alright with the megaflo and not interfere with its operation?

 

[sasha0120]

Not sure you've got the room but a Dab E.SyBox would be your solution.

DAB ESYBOX and ESYTANK Cold Water Booster & Storage Tank

The DAB E.sybox and E.sytank is our best selling all in one booster set and water storage tank for domestic and residential applications. The ESYTANK is a potable (drinking) water storage tank designed specifically for simple integration with the ESYBOX electronic water booster system. The...

www.completepumpsupplies.co.uk

I couldnt tell from the description, is that an accumulator?

 

[ShaunCorbs]

Thanks for your input. Do you know if the pump will work alright with the megaflo and not interfere with its operation?

Yep be like you just have a decent mains pressure the dab sys is decent and quiet

 

[sasha0120]

Yep be like you just have a decent mains pressure the dab sys is decent and quiet

Thanks for your prompt reply! The description for the dabs systems says that it doesnt require any additional pump or tank? Do you still think we need a tank? Its for a rented property with a max occupancy of 4.

 

[Timmy D]

Thanks for your input. Do you know if the pump will work alright with the megaflo and not interfere with its operation?

It will work fine with the mega flow but a couple of things to consider.

The tank/pump will have to be connected to both the megaflow supply pipework and the cold supplies to the bathrooms and kitchen. You may have a separate feed to the bathrooms and kitchen making this difficult. Ensure the installers are going to pump it all, and the kit they use is rated for wholesome/drinking water.

The tank will need to be serviced/cleaned periodically.

Also bear in mind that as the toilets will likely be connected to the pump, a midnight toilet trip/flush will trigger the pump.

And finally, as Shaun mentioned, 800L gives you a good buffer, but 800L plus your existing hot water tank puts you at around 1 ton of weight. This is a lot, and needs to be taken into consideration when locating the additional storage. The weight, unless properly distributed/reinforced, will over time crack the ceiling plaster in the below flat.

The average design capacity of UK joisted floors is 150kg per m2. Far below what’s being proposed.

I don’t know how many properties are in the building, but if you can get a few people on board, the costs are not far off getting a new mains from the street and running new pipe up the building.

 

[ShaunCorbs]

For our recommendation you will require

https://www.completepumpsupplies.co.uk/dab-e-sybox-and-tank

https://www.completepumpsupplies.co.uk/dab-e-sytank-500-litre-tank

https://www.completepumpsupplies.co.uk/dab-e-sytank-coupling-kit

And then just divert the mains cold water straight from your stop tap to the tank and then run another 22mm feed out to the pipe that was connected to the stop tap

 

[Timmy D]

Thanks for your prompt reply! The description for the dabs systems says that it doesnt require any additional pump or tank? Do you still think we need a tank? Its for a rented property with a max occupancy of 4.

The dab is a combined tank/pump unit. So it doesn’t require “another” pump of tank.

Wether it’s a dab or another brand (separate tank/pump), you’re gonna need a pump/tank solution. You've got no flow, you can’t pump no flow.

Max you can pump the mains without a tank is 12lpm which is not suitable for a property with 2 bathrooms.

At peak times with no flow for topping up the tank, 4 people could run through 400-500 litres in the morning, so Shaun’s recommendation of 800L, sounds about right.

 

[sasha0120]

For our recommendation you will require

https://www.completepumpsupplies.co.uk/dab-e-sybox-and-tank

https://www.completepumpsupplies.co.uk/dab-e-sytank-500-litre-tank

https://www.completepumpsupplies.co.uk/dab-e-sytank-coupling-kit

And then just divert the mains cold water straight from your stop tap to the tank and then run another 22mm feed out to the pipe that was connected to the stop tap

Thanks Shaun. There was a cold water tank in the property when we moved in but it was disconnected when the megaflo was installed 7 years ago. The new megaflo boiler replaced an old one. Currently the no water situation happens only for 20-30mins in the mornings so is it worth just buying the dabs as it has a 500L tank in it? Also in case the existing old cold water tank is usable, would it be possible to reconnect the old tank to the dabs sytem?

 

[ShaunCorbs]

480l at 15lpm would last approximately 30 mins it’s cutting it close and that’s being fully drained which I wouldn’t recommend as It could run dry

 

[Timmy D]

Just to add, if these solutions have been proposed by the same people who installed the mega flow, I’d be hesitant to use them as they should have spotted this before recommending the megaflow.

 

[sasha0120]

480l at 15lpm would last approximately 30 mins it’s cutting it close and that’s being fully drained which I wouldn’t recommend as It could run dry

Is that assuming two showers running simultaneously for 30mins?

 

[ShaunCorbs]

Is that assuming two showers running simultaneously for 30mins?

No that’s one shower / outlet at 15lpm most showers are 12-15 litres per minute so two your using 30 lpm so 16 minutes with a 480 l or 35 minutes with both tanks

 

[sasha0120]

No that’s one shower / outlet at 15lpm most showers are 12-15 litres per minute so two your using 30 lpm so 16 minutes with a 480 l or 35 minutes with both tanks

thanks!

 

[John.g]

Just to add, if these solutions have been proposed by the same people who installed the mega flow, I’d be hesitant to use them as they should have spotted this before recommending the megaflow.

How or what was the OP using previous to this megaflow installation?

 

[ShaunCorbs]

How or what was the OP using previous to this megaflow installation?

Gravity cold tank and cylinder

 

[John.g]

Why not (OP) measure his actual shower flowrate(s), the DAB VS pump pressure can then be set to match this and he may find that a little or no compromise will result in no extra tank capacity required.

 

[John.g]

If the flowrate through a cold tap is measured during this bad morning period then that will give a good idea of what will be making up into the DAB tank and even if its as low as 6 LPM that will augment his storage and give effectively ~ 700 ltrs. (35 mins)

 

[ShaunCorbs]

If the flowrate through a cold tap is measured during this bad morning period then that will give a good idea of what will be making up into the DAB tank and even if its as low as 6 LPM that will augment his storage and give effectively ~ 700 ltrs. (35 mins)

0lpm he doesn’t have any water sometimes

 

[Chuck]

0lpm he doesn’t have any water sometimes

I'd have thought that this is an issue for the owners of the block to remedy rather than individual flat owners.

 

[sasha0120]

I'd have thought that this is an issue for the owners of the block to remedy rather than individual flat owners.

yes I thought so too but they are refusing to as the other flat at our level has its own tank and so its just our flat that seems to be impacted

 

[John.g]

When you had your own tank 7/8 years ago you would/should still have had one tap fed off the mains so did you still have zero flow through this tap at peak times?.

 

[ShaunCorbs]

I'd have thought that this is an issue for the owners of the block to remedy rather than individual flat owners.

Might be private owned also bit bad of the water supplier to say not our problem aswell tbh

 

[sasha0120]

When you had your own tank 7/8 years ago you would/should still have had one tap fed off the mains so did you still have zero flow through this tap at peak times?.

yes

 

[John.g]

Thanks, would IMO be a big help if you can measure your shower flows during normal supply times to help in sizing your tank.

 

[Chuck]

yes I thought so too but they are refusing to as the other flat at our level has its own tank and so its just our flat that seems to be impacted

Hmm, seems like a fairly complicated situation.

Anyway, you need a reliable supply of potable water. So, if you do decide to fix the symptoms rather than the cause then make sure that any tank and/or pump you install is certified as suitable for potable water and is properly maintained.

 

[sasha0120]

Thanks, would IMO be a big help if you can measure your shower flows during normal supply times to help in sizing your tank.

I have the pressure reading if that's of any use? It was a little less than 1 bar.

 

[John.g]

When you have your shower running normally at your desired flow and temperature hold a bucket or dish under it for exactly one minute and measure this amount in litres or pints. You can also note the pressure as well with shower running normally.

 

[SJB060685]

Max you can pump the mains without a tank is 12lpm which is not suitable for a property with 2 bathrooms.

Can you explain why 12lpm is the max mate. It's been a long time since I did my relavent courses.

 

[Chuck]

I've been racking my brain and have remembered something, e.g.

South West Water

Providing reliable, efficient and high quality drinking water and waste water services throughout Cornwall and Devon, plus servicing small areas of Dorset and Somerset.

www.southwestwater.co.uk

Water companies have "a statutory requirement to supply water by gravity continuously for domestic purposes at a pressure that will; ‘reach the top of the top-most storey of every building’ (Water Industry Act 1991 Section 65)."

This is in addition to the OFWAT minimum pressure at the end of the communication pipe. So, I think it would be worth going back to the water company and making a complaint about non-compliance.

@SJB060685 - I think that the 12 lpm limit is to stop you starving neighbouring properties.

 

[John.g]

If you had 3 floors even with each only 2.5M high then a pressure of 0.75 bar will reach the top of the the third floor so you might argue that 1.0 bar (dynamic) would be more than adequate and it would, if you had > 22mm piping. 1 bar should theoretically flow 20 LPM to each floor (total 60 LPM) with 22mm piping but if 15mm is used then ~ 2.8 bar is required for the same flow rates. 1.6 bar minimum is still required at a flow rate of 10 LPM to each floor with 15mm piping so surely there is a requirement (and not from the water board(s)) to install adequately sized piping for each application.
1.0 bar dynamic will only give ~ 6 LPM to each floor with 15mm piping, assuming in all cases that a storage tank is being filled, also IMO the op will receive 0 LPM if the two floors below are flowing ~ 10 LPM each @ 1 bar dynamic.

 

[Chuck]

If you had 3 floors even with each only 2.5M high then a pressure of 0.75 bar will reach the top of the the third floor so you might argue that 1.0 bar (dynamic) would be more than adequate and it would,

During the periods when when the supply is '0 lpm' the water company is not 'supply[ing] water continuously', is it?

 

[John.g]

No, are they then obliged to either run a separate supply to the OP (the owner) or pay to upsize the existing (3 flat) piping? They also state that "where our communication pipe joins your supply pipe you should be able to fill a 2 litre bottle in less than approximately 13 seconds." so does this imply that they are only obliged to supply 10.9 LPM continuously?,

 

[Ant87]

Am I right in thinking that an unvented cylinder requires a minimum of 1.5bar working pressure and around 20l/min so even if SWW meet their minimum obligations of 0.7bar (at pavement level) and 10l/min then issues will still be present?

Something like a Stuart Turner Flomate might be an option which is an all in one stored water (break) pump set.
Dab E.sybox are extremely good units but might be overkill?

You are correct in saying that legally you can pump up to 12l/min directly from the mains with no break tank. Salamander HomeBoost is a direct to mains booster pump which will pump at 12l/min (1.6bar i think) however would still not be adequate for an unvented cylinder.

 

[Timmy D]

Can you explain why 12lpm is the max mate. It's been a long time since I did my relavent courses.

Water regs. As Chuck mentioned, to stop the mains supply running dry during peak periods.